Method and apparatus for positioning filaments in filament lamps



May 2, 1967 R. H. LESHER 3,317,263 METHOD AND APPARATUS FOR POSITIONINGJ F'ILAMENTS IN FILAMENT LAMPS Filed Dec. 9, 1963 2 Sheets-Sheet 1INVENTOR.

RALPH H. LESHER, DECEASED BY ROBERT W. LESHER, ADMINISTRATOR BY MMJMArron/vars R. H. LESHER AP May 2, 1967 3,317,263 METHOD AND PARATUS FORPOSITIONING FILAME'NTS IN FILAMENT LAMPS 2 Sheets-Sheet 2 Filed Dec. 9,1963 ATToRA/Ew United States Patent Office 3,317,263 Patented May 2,1967 3,317,263 METHOD AND APPARATUS FOR PGSITIDNING FILAMENTS INFILAMENT LAMPS Ralph H. Lesher, deceased, late of Minneapolis, Minn byRobert W. Lesher, administrator, Minneapolis, Minn., assignor to JosephR. Brink, Minneapolis, Minn.

Filed Dec. 9, 1963, Ser. No. 329,318 6 Claims. (Cl. 316-43) Thisinvention relates generally to the production of filament lamps, andmore particularly it rel-ates to a novel tool and method for positioningthe filaments in the bulbs of filament lamps in their proper focalpositions.

Generally, the tool and apparatus of the present invention comprises abase member, a parabolic reflector carried by the base member, a seatdefined by the base member and adapted to receive the bulbs of the lampsto be adjusted, means for initially adjusting the reflector relative tothe seat by the use of a master filament lamp, means for releasablyretaining the bulbs of the lamps to be adjusted against the seat,whereby the filaments of the lamps may be adjusted by moving the stemuntil a given portion of the filament intersects its similarly givenportion of the filament image produced by said reflector when viewingthe filament from a generally lateral viewpoint; and the presentinvention also comprises a novel method for accomplishing theabove-noted adjustment of the lamp filaments.

It is known that glare from electric filament lamps results from thelamp filaments being incorrectly positioned within the lamps and not inthe proper focal position. The glare from electric filament lamps hasbeen a long known problem, particularly with electric filament lamps ofthe seal beam headlight type for automotive vehicles; and theelimination of glare from filament lamps would permit the elimination ofthe costly fluting of the lamp lenses, together with the elimination ofthe dimming equipment for filament lamps used on automotive vehicles.

In view of the above known problems and characteristics of filamentlamps, it is an important object of the present invention to provide atool and apparatus for the quick and easy positioning of the filamentsin the bulbs of filament lamps in their proper focal positions duringmanufacture.

Another important object of the present invention is the provision of anovel method for accomplishing the above-noted adjustment or filamentpositioning of the lamps.

Another object of the present invention is the provision of a novel toolor apparatus and novel method for correctly positioning filaments inelectric lamps which initially utilizes a master filament lamp having agenerally perfectly focused filament, and which method and apparatus maybe used to manufacture innumerable quantities of lamps having generallyperfectly focused filaments, after the initial adjustment of the tool.

A further object of the present invention resides in the provision of anovel tool and method for the production of filament lamps havinggenerally perfectly focused filaments so as to eliminate the above-notedproblem of glare.

Other objects of the present invention reside in the provision of anovel method and apparatus for the production of filament lamps havinggenerally perfectly focused filaments which are simple in theiroperation, may be economically utilized, and also provide for theeificient and economic production of filament lamps.

Other objects and advantages of the present invention will becomeapparent from a consideration of the following detailed specification,appended claims and attached drawings.

Referring to the drawings, wherein like reference characters indicatelike parts or elements throughout the several views:

FIG. 1 is a view in side elevation of the tool and apparatus for thepresent invention;

FIG. 2 is a reduced view in rear elevation thereof;

FIG. 3 is a view in front elevation thereof;

FIG. 4 is an enlarged view in section taken on the line 4-4 of FIG. 3;

FIG. 5 is a reduced view corresponding to FIG. 4 of the drawings, butshowing a filament lamp positioned thereagainst and also showing some ofthe steps of the novel method of this invention;

FIG. 6 is a view corresponding to FIG. 5, and showing further steps ofthe novel method of this invention, some portions of the structure beingbroken away;

FIG. 7 is a view in section of a filament lamp showing still furthersteps of the novel method of this invention;

FIG. 8 is a view in side elevation of an alternative type of tool foranother type of filament lamp;

FIG. 9 is an enlarged view in perspective of the structure shown in FIG.8 showing the overlapping position of the filament and the filamentimage, as described hereinafter; and

FIG. 10 is a view in perspective corresponding to that shown in FIG. 9,"but showing the intersecting position of tllie filament and thefilament image, as described hereina ter.

It is noted that the terms side elevation, rear elevation and frontelevation as used in describing the above figures of the drawings areused only in a relative sense with respect to one another forconvenience of description, and are not intended to limit the actualpositions of the devices as they maybe utilized.

Referring more particularly to the drawings, the novel tool andapparatus of the present invention shown particularly in FIGS. 1-4 ofthe drawings comprises a trisection base member, represented generallyby the reference numeral 1. The three sections of the base member 1 areeach represented by the reference numeral 2, and the inner surfaces 3thereof are formed to generally define portions of a paraboloid. Thebase member 1 further comprises a tri-section insert plate correspondinggenerally to the configuration of the tri-sections 2 and secured theretoby suitable fasteners 5. The insert plate 4 is further formed to definean elongated generally tubular handle portion 6, as shown particularlyin FIG. 4 of the drawings.

In accordance with this invention, the tool or apparatus furthercomprises a parabolic or paraboloidal reflector, represented generallyby the reference numeral 7, carried by the base member 1 and mountedtherein for adjustable movements with respect thereto. The tool furthercomprises a plurality of spaced seat elements 8, each one defined by adifferent one of the sections 2 of the base memher 1. The seat elements8 are sometimes referred to herein collectively .as a seat, and it isnoted that in some applications, the seat may be defined by the outercircumferential edge portion 9 of the paraboloidal reflector 7. Thereflector 7 is mounted by suitable means, described particularlyhereinafter, within the base member 1 for longitudinal adjustmentrelative to the base member 1, and also relative to the seat element 8.The reflector 7 defines an axially outwardly extending spindle 10 ofsmaller diameter than the bore of the handle portions 6 of the basemember .1, and the end portion of the spindle 10 fits within abearing-acting bore defined in the inner end portion 11 of an adjustmentscrew rod 12. The adjustment screw rod 12 is screw threaded within thebore of the handle portion 6 and may be adjusted by a suitable tool, notshown, adapted to fit the slotted outer end portion 13 thereof. Thereflector 7 is held in its desired adjusted position by means of a setscrew 1'4 screw threaded into the handle portion 6, as shownparticularly in FIGS. 4 and of the drawings.

The tool and apparatus of the present invention further comprises meansfor releasably retaining the bulbs of the lamps to be adjusted againstthe seat or seat elements 8 of the tool. Said means comp-rises aplurality of inwardly biased roller elements, each represented by thereference numeral 15, and each one positioned generally adjacent adifferent one of the seat elements 8, as shown particularly in FIGS. 1and 3 of the drawings. The outer generally cylindrical surface of eachof the roller elements is generally arcuately formed for suitableengagement with the bulb surface of the lamp to be adjusted. As shown indetail in FIGS. 1 and 4 of the drawings, each of the roller elementscomprises a bifurcated bracket 16 for mounting the associated roller anda longitudinally extending spring member 17 adjustably secured to theassociated section 2 of the base member .1 by means of an elongatedbracket .18 having a channel defined therein. It is further noted thatthe roller elements 15 are located longitudinally of the base member 1,or axially of the paraboloidal reflector 7, for engagement of the bulbsurfaces of the lamps to be adjusted at positions over the greatesttransverse diameter of the bulbs of said lamps, as shown for example inFIGS. 5 and 6 of the drawings. The roller elements 15 are spring biasedin an inward direction between a position in engagement with the bulbsurfaces of the lamps to be adjusted, as shown by full lines in FIG. 5,and outer positions upon removal or insertion of the lamps, asrepresented by the dotted lines in FIG. 5 of the drawings.

When using the tool or apparatus of the present invention, the reflector7 is initially adjusted with respect to the base member 1 by use of amaster filament lamp, not shown, of the same size as the lamps to beadjusted and having a filament previously determined to be perfectlyfocused. The master filament bulb, not shown, is positioned within thetool and the reflector 7 is thereafter adjusted by means of theadjustment screw rod 12 to a position wherein a given portion, such asthe tip, of the filament of the master filament lamp intersects asimilarly given point or portion of the filament image produced by thereflector when viewing the filament from a generally lateral viewpoint.When the reflector 7 has been so adjusted, the same is held to itsdesired position by means of the set screw 14 and further adjust-ment ofthe reflector 7 will be unnecessary for later use in the production offilament lamps of the same diameter as the master filament lamp.Thereafter, the tool or apparatus of the present invention may be usedfor the production of filament lamps having generally perfectly focusedfilaments, by inserting the lamps within the roller elements 15 andagainst the seat elements 8. Then, as will be particularly describedhereinafter, the lamps are adjusted by moving the stem thereof until agiven portion, such as the tip of the filament intersects a similarlygiven portion of the filament image produced by the reflector 7 whenviewing the lamp filament from a generally lateral viewpoint.

The tool or apparatus of the present invention further comprises meansfor ejecting the adjusted lamps from the tool, and as shown particularlyin FIGS. 1, 2 and 4 of the drawings, said ejection means comprises aplurality of ejector rods 19. The ejector rods 19 have axially extendinginner portions 20 received within corresponding slots 21 defined in thehandle portion 6 of the base member 1. The ejector rods 19 also compriseintermediate transverse portions 22 and outer axially extending portions23 received within corresponding bearing bores 24 within the sections 2of the base member 1, as shown particularly in FIGS. 2 and 4 of thedrawings. Upon pushing button 25 adjacent the end of the handle portion6, the outer portions 23 of the ejector 4 rods 19 will engage the bulbof the lamp within the tool and eject the same.

Method With respect to the novel method of the present invention, thesame may be practiced according to the following specific steps some ofwhich may be eleminated without deviating from the scope of thisinvention. Initially, the tool is adjusted by placing therein a masterfilament lamp of the same size and having a generally perfectly focusedfilament, and the reflector 7 is adjusted by means of the adjustmentscrew rod 1 2 so as to perfectly align the filament image in themirrored reflector 7 with the filament of the master filament lamp.Then, the tool may be thereafter used to properly adjust the filamentsof a practically infinite number of lamps of the same size as the toolwhich has been preadjusted by the master filament lamp. This is donewith each lamp to be so adjusted by first mounting or placing the bulb27 within the tool, and then the filament carried by the stem 26 isplaced within the bulb 27 through the neck 28 thereof. Of course, thefilament could be placed within the bulb 27 prior to mounting each lampin the tool. In any event, the outer generally spheroidal surface of thefilament carrying bulb 27 is positioned against the above-noted seat ofthe tool.

Continuing with the procedure or method for properly adjusting thefilament of each lamp, after the filament carrying stem 26 has beenplaced within the bulb 27, the stem is adjusted so as to slightlyoverlap (approximately /8 in most cases) the filament image produced inthe mirrored reflector 7, as particularly shown in FIG. 5 of thedrawings. Then, the bulb neck 28 (dotted lines in FIG. 5) and the flaredportion 29 of the stem 26 are heated so as to seal the bulb neck 28 tothe stem 26. Then, the excess or the major portion of the bulb neck 28(dotted lines in FIG. 5) is removed. This may be done by applyingpressure (approximately 4 pounds) to the neck 28, heating the same andthen tapping the neck 28 to remove it. The next step is to reheat theremaining portion 30 of the bulb neck 28 and the adjacent sealed portion29 of the stem 26, after which the filament is readjusted to theposition illustrated in FIG. 6 of the drawings, wherein the stem 26 hasbeen moved, such as by gripping the extended evacuating portion 31thereof, until a given end portion of the filament intersects asimilarly given portion of the filament image produced by the mirroredreflector when viewing the filament from a generally lateral viewpoint.The respective lines of sight used by the operators when aligning thefilament and the filament image are illustrated by broken lines in FIGS.5 and 6 of the drawings, the same being only intended to be illustrativeof the invention. By the use of the above-method, every one of the lampsproduced will have a perfectly focused filament, and the word perfect orgenerally perfect is intended to mean vastly improved perfection in theproper placement of the filament over the previous practice, it beingrecognized that the word perfect may have various meanings, includingmicroscopic or nearly infinitesimal variations only ascertainable undervery exacting laboratory conditions.

After the filament has been adjusted to its proper and desired locationin the above manner so as to eliminate glare, the interior of the bulb27 is evacuated in the usual manner through the evacuating portion 31,and the evacuating portion 31 is then sealed, in the usual practice.Then, the proper lamp base 32 (see FIG. 7) is mounted on the lamp,proper contact being made with the filament leads 33, 34. See FIGS. 5-7.

Other embodiments A novel filament has been disclosed in the presentinvention, the same comprising a pair of axially spaced filament coils35, 36 connected in series With a support wire 37 connected therebetweenand engaging the end portion of the stem 26, as shown for example inFIG. 6 of the drawings. The axially outer coil 36 is connected to thefilament lead 33, and the axially inner end coil 36 is connected to thefilament lead 34. It is noted that the relative size of the filamentsshown in the drawings has been greatly exaggeratedso as to particularlyillustrate the construction thereof.

A modified embodiment of the tool and apparatus of the present inventionis shown in FIGS. 81(), which is a tool particularly constructed for usewith filament lamps having a spherical bulb, such as smaller sizes offilament lamps, not having their own lens as is shown in FIGS. 5-7. Inthis embodiment, the tool body 38 has its reflector surface 39 ground tothe desired configuration relative to a master filament lamp having agenerally perfectly focused filament, and the same is not adjustable asis the tool initially described above. Suitable spring biased retainerelements 40 are secured to the tool body 38, as illustrated in FIG. 8,for example. Other- Wise, the practice of the present invention is thesame with the embodiment shown in FIGS. 8-10 as in the embodiment firstdescribed above. Further, the parts or elements of this embodiment shownin FIGS. 810 which correspond to like or respective parts or elements ofthe embodiment shown in FIGS. 1-7 are denoted by the use of'the samenumerals with prime marks added thereto.

With respect to all of the above, it is further noted that the sightlines (broken lines in the drawings) are for illustration only; andgenerally any convenient line of sight may be selected and still givesatisfactory results, having in mind the refraction through the bulband/or lens (if any) of the lamp. The refraction is not consequentialfrom a broad standpoint since refraction is also a factor when makingthe original adjustment with the master filament lamp.

With respect to the operation of this invention, the same has beenimplicitly described above. It is also noted that this invention hasbeen tested and found to be completely satisfactory for theaccomplishment of the abovenoted objects; and while preferredembodiments thereof, in which the principles of the present inventionhave been incorporated, have been shown and described above, it shouldbe specifically understood that the same may be modified withoutdeparture from the scope and spirit of the appended claims.

It is claimed:

1. A tool for use in positioning filaments in the bulbs of filamentlamps in their proper focal position, said tool comprising:

(a) a base member,

(b) a parabolic reflector carried by said base member,

(c) a seat defined by said base member and adapted to receive the bulbsof said lamps,

((1) means for initially adjusting said reflector relative to said seatby use of a master filament lamp of the same size as said lamps to beadjusted and having a generally perfectly focused filament,

(e) means for releasably retaining the bulbs of lamps to be adjustedagainst said seat, said means comprising a plurality of inwardly biasedroller elements each one positioned adjacent a different one of saidseat elements and said roller elements being located longitudinally ofsaid base member for engagement with this bulb surfaces of the lamps tobe adjusted at positions over the greatest transverse diameter of thebulbs, and

(f) whereby the filaments of the lamps may be adjusted by moving thestern until a given portion of the filament intersects a similarly givenportion of the filament image produced by said reflector when viewingthe filament from a generally lateral viewpoint.

2. A tool for use in positioning filaments in the bulbs of filamentlamps in their proper focal position, said tool comprising:

(a) a base member,

(b) a parabolic reflector carried by said base member,

(0) a seat defined by said base member and adapted to receive the bulbsof said lamps,

(d) means for initially adjusting said reflector relative to said seatby use of a master filament lamp of the same size as said lamps to beadjusted and having a generally perfectly focused filament,

(e) means for releasably retaining the bulbs of lamps to be adjustedagainst said seat,

(f) whereby the filaments of the lamps may be adjusted by moving thestem until a given portion of the filament intersects a similarly givenportion of the filament image produced by said reflector when viewingthe filament from a generally lateral viewpoint, and

(g) means for ejecting said adjusted lamps from said tool.

3. A tool for use in positioning filaments in the bulbs of filamentlamps in their proper focal position, said tool comprising:

(a) a base member,

(b) a parabolic reflector carried by said base member,

(c) a plurality of spaced seat elements defined by said base member andadapted to receive the bulbs of the lamps to be adjusted,

(d) means mounting said reflector Within said base a member forlongitudinal adjustment relative to said seat elements by use of amaster filament lamp of the same size as said lamps to be adjusted andhaving a generally perfectly focused filament,

(e) means for releasably retaining the bulbs of the lamps to be adjustedagainst said seat elements, said means comprising a plurality ofinwardly biased roller elements each one positioned adjacent a different one of said seat elements and said roller elements being locatedlongitudinally of said base member for engagement of the bulb surfacesof the lamps to be adjusted at positions over the greatest transversediameter of the bulb,

(f) whereby the filaments of the lamps may be adjusted by moving thestem until a given portion of the filament intersects a similarly givenportion of the filament image produced by said reflector when viewingthe filament from a generally lateral viewpoint, and

(g) means for ejecting said adjusted lamps from said tool.

4. The method of positioning the filament in the bulb of a filament lampin its proper focal position, said method comprising:

(a) placing the stem-carried filament within the bulb,

(b) positioning the outer generally spheroidal surface of thefilament-carrying bulb in a seat which has been preadjusted relative toa parabolic reflector by use of a master filament lamp of the same sizeas said lamp to be adjusted and having a generally perfectly focusedfilament, and

(c) adjusting the position of the filament of the lamp to be adjusted bymoving the stem until a given portion of the filament intersects asimilarly given portion on the filament image produced by said reflectorwhen viewing said filament from a generally lateral viewpoint.

5. The method of positioning the filament in the bulb of a filament lampin its proper focal position, said method comprising:

(a) placing the stem-carried filament within the bulb,

(b) positioning the outer generally spheroidal surface of thefilament-carrying bulb in a seat which has been preadjusted relative toa parabolic reflector by use of a master filament lamp of the same sizeas said lamp to be adjusted and having a generally perfectly focusedfilament,

(c) adjusting the position of the filament of the lamp to be adjusted bymoving the stem until a given portion of the filament overlaps asimilarly given portion on the filament image produced by said reflectorwhen viewing said filament from a generally lateral viewpoint.

(d) heating and sealing the stem to the bulb neck, and

(e) before said stern and bulb neck have cooled, re-

adjusting the position of the filament by moving the stem until a givenportion of the filament intersects a similarly given portion on thefilament image produced by said reflector when viewing the filament froma generally lateral viewpoint.

6. The method of positioning the filament in the bulb of the filamentlamp in its proper focal position, said method comprising:

(a) placing the stem-carried filament within the bulb,

(b) positioning the outer generally spheroidal surface of thefilament-carrying bulb in a seat which has been preadjusted relative toa parabolic reflector by use of a master filament lamp of the same sizeand having a generally perfectly focused filament,

(c) adjusting the position of the filament of the lamp to be adjusted bymoving the stern until a given portion of the filament overlaps asimilarly given portion on the filament image produced by said reflectorwhen viewing said filament from a generally lateral viewpoint,

(d) heating and sealing the bulb neck to the filament carrying stem,

(e) removing the excess neck portion outwardly of its seal to the stem,

(f) after reheating the bulb neck and stem, readjusting the position ofthe filament by moving the stem until a given portion of the filamentintersects a similarly given portion on the filament image produced bysaid reflector when viewing the filament from a generally lateralviewpoint,

(g) evacuating the bulb and thereafter sealing the evacuating portion ofthe stern, and

(h) mounting a base onto the bulb.

References Cited by the Eriaminer UNITED STATES PATENTS 2,947,854 8/1960Lozeau 240-441 FRANK E. BAILEY, Primary Examiner.

1. A TOOL FOR USE IN POSITIONING FILAMENTS IN THE BULBS OF FILAMENTLAMPS IN THEIR PROPER FOCAL POSITION, SAID TOOL COMPRISING: (A) A BASEMEMBER, (B) A PARABOLIC REFLECTOR CARRIED BY SAID BASE MEMBER, (C) ASEAT DEFINED BY SAID BASE MEMBER AND ADAPTED TO RECEIVE THE BULBS OFSAID LAMPS, (D) MEANS FOR INITIALLY ADJUSTING SAID REFLECTOR RELATIVE TOSAID SEAT BY USE OF A MASTER FILAMENT LAMP OF THE SAME SIZE AS SAIDLAMPS TO BE ADJUSTED AND HAVING A GENERALLY PERFECTLY FOCUSED FILAMENT,(E) MEANS FOR RELEASABLY RETAINING THE BULBS OF LAMPS TO BE ADJUSTEDAGAINST SAID SEAT, SAID MEANS COMPRISING A PLURALITY OF INWARDLY BIASEDROLLER ELEMENTS EACH ONE POSITIONED ADJACENT A DIFFERENT ONE OF SAIDSEAT ELEMENTS AND SAID ROLLER ELEMENTS BEING LOCATED